Improved coal-screen



N.PETER5. PHOT0-UTHOGRAPHER. WASHINGYON. n C,

UNITED STATES ArnNr JOHN A. ROBINSON, OF PITTSTON, PENNSYLVANIA,

IMPROVED COAL-SCREEN.

To all whom it may concern: v

Be it known that I, JOHN A. ROBINSON, of Pittston, in the county ofLuzerne and State of Pennsylvania, have invented a new and ImprovedCoal-Screen; and I do hereby declare that the following` is a full,clear, and exact description thereof, which will enable others skilledin the art to make and use the same, reference being had to theaccompany! ing drawings, forming part of this specication, in which-Figure l is a plan or top view of my invention; Fig. 2, an end view ofthe same, partly in section.

Similar letters of reference indicate like p rtS.

This invention relates to a new and iinproved screen for screeningcoa-l, designed more especially for screening coal preparatory tocracking the same; and it consists in constructing the screen of xed andadjustable or slidingl bars, arranged in such a manner that the screenmay be graduated to let through lumps of coal of greater or less size asmaybe required, and the dust and line coal not necessary to be crackednot allowed, as hitherto, to pass through the cracker.

A B represent two inclined screens, which are placed one over the otherin a suitable framing, the lower screen, B, having fixed bars a placedat such a distance apart as to allow the coal dust and dirt to passbetween them, while the fine coal which cannot pass through said screenpasses directly, by its own gravity, to the grading-screen.

The upper screen, A, is formed of two sets of bars, b b. The bars b arexed, their ends being permanently secured to two parallel rails, c c,one of which is considerably more elevated than the other so that thebars b will have a requisite degree of elevation.

Between the fixed bars b there are placed movable or sliding bars b',the ends of which are secured to sliding rails d d, which are tted ingrooves in the rails c c, and are connected at one end by a rod, e,which is attached at its center by a link, f, with the lower end of alever, O. Bymoving or adjusting this lever O the screen A may be madecoarser or finer, owing to the adjustment of the bars b. The coal isdumped from the cars upon the screen A, and all large coal whichrequires to be cracked is not allowed to pass through said screen, butpasses directly into the cracker t0 be crushed or broken into lumps ofrequisite size for burning, while the dust, dirt, and coal that isalready small enough passes through the screen A and falls upon screenB, the dust and dirt, as before stated, passing through B, while thecoal passes to the grading-screen.

By this means it will be seen that a great saving is effected in coal,as the coal which is sufficiently tine without cracking is not allowedto pass through the cracker to be further reduced, and the wasteattending that unnecessary cracking operation is consequently avoided.

The sliding or adjustable bars b of the screen A also effect a greatsaving in time, as by their use the changing of screens from ne tocoarse, and vice versa, is avoided, and the amount of large coal fed tothe cracker may be regulated as desired-that is to say, coal of greateror less size may be allowed to pass through the screen A without beingfed t0 the cracker.

I claim as new and desire to secure by Letters Patent- 1. The employmentor use of screens A B, arranged substantially as shown and described,for the purpose of screening coal in its discharge to the cracker andgradingscreen, as set forth.

2. Constructing the upper screen, A, with movable or adjustable bars,arranged to operate substantially as herein described.

JOHN A. ROBINSON.

Witnesses:

O. M. MCDOWALL, It. D. Lncon.

